It’s a given that movie science needs to be taken with a big fat grain of salt, but even by those standards, some films seem to push the limits of implausibility more than others. And I’m not just talking about obvious nonsense like superpower-bestowing radioactive spider bites here.

So some science-minded folks are fighting back, playfully, by investigating and possibly debunking some of the crazier claims made by Hollywood. On NPR, pop culture’s favorite astrophysicist Neil deGrasse Tyson discusses the viability (or lack thereof) of 007’s coolest gadgets, while over on Mythbusters, the hosts cast doubt on James Cameron‘s insistence that Jack had to die at the end of Titanic.

First, we have a video clip from Mythbusters in which Cameron and hosts Jamie Hyneman and Adam Savage join forces to find out once and for all whether Jack could’ve survived the sinking of the Titanic.

The issue of whether Rose could’ve saved Jack’s life by sharing her makeshift life raft has been floating around (no pun intended) for years, but it’s received fresh attention in recent months thanks to the 3D rerelease of Titanic. Cameron has previously explained that “it’s not a question of room, it’s a question of buoyancy,” but the results suggest that the pair could’ve gotten around even that if only they’d had better problem-solving skills.

Then again, however, no amount of ingenuity or generosity on Jack or Rose’s part around Cameron’s real explanation for Jack’s death. “The script says Jack dies,” Cameron shrugs. “He has to die.[…] The dude’s going down.” Now that sounds like the brutal, honest truth.

Meanwhile, NPR’s Morning Edition is celebrating the 50th anniversary of the Bond film franchise by, among other things, calling over Tyson to explain which 007 gadgets are plausible and which ones are pure fiction.

The bullet-deflecting magnetic wristwatch from Live and Let Die, for example, gets a big fat no. Pointing out that bullets are made of non-magnetic lead, Tyson explains, “So you’re not deflecting bullets with your magnetic device.” The ring that emits high-frequency waves to break glass, on the other hand? “Rigid, brittle things can break if you find the resonant frequency,” Tyson says. “[T]he fact that you can carry it on your ring — that’s a little harder to take. But it’s James Bond, and so he gets stuff that you don’t.”

But the implausibility of Bond’s tools doesn’t necessarily stop Tyson — or anyone else — from coveting some of them. “I want one of those,” he said in reference to the invisible Aston Martin from Die Another Day. But “we haven’t figured out really how to do that yet.” Listen to the full five-minute interview on NPR.org.